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U.S. airstrikes hit ISIS near Mosul Dam

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Growing concern Mosul Dam is not being properly maintained by ISIS, U.S. official says

U.S. intelligence agencies are watching the Haditha Dam, the official says

U.S. fighter jets and drones carry out airstrikes near Mosul and Irbil, the U.S. military says

Yazidi leader tells a British broadcaster the death toll in Kojo village is at least 350

U.S. warplanes on Saturday pounded a series of extremist militant targets in what officials say is part of an effort to retake a key piece of infrastructure in northern Iraq -- Mosul Dam.

The airstrikes against fighters of the so-called Islamic State come amid growing concern that the dam is not being properly maintained and could rupture, a U.S. official familiar with the details told CNN.

Engineering studies have shown that a failure of the dam would be catastrophic, resulting in flooding all the way to Baghdad, the official said on condition of anonymity.

Mosul Dam is Iraq's largest hydroelectric dam, and it sits on the Tigris Rivers about 50 kilometers (31 miles) north of the city of Mosul. ISIS fighters took control of the dam this month following fierce fighting.

The United States estimates there may be up to 400 ISIS fighters in and around the dam complex, said the U.S. official.

The U.S. military confirmed a mix of fighter jets and drones carried out nine airstrikes near Mosul and the Kurdish regional capital of Irbil. The strikes targeted armored vehicles being used by ISIS fighters, it said.

U.S. Central Command declined to provide further details, citing security of its personnel.

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Yazidis take refuge from ISIS militants

Iraqi refugees fleeing ISIS – A Yazidi family from Sinjar cleans a spot for themselves in a derelict building that houses more than a thousand other refugees on Thursday, August 14, in Zakho, Iraq.

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Iraqi refugees fleeing ISIS – A woman and child sit in the makeshift housing on Thursday.

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Iraqi refugees fleeing ISIS – A Yazidi woman holds her baby while crossing Peshkhabour bridge from Syria back into Kurdish-controlled Iraq on Tuesday, August 12.

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Iraqi refugees fleeing ISIS – Entire families carry nothing but the clothes on their back. Some are barefoot. And not everyone who set out on the arduous journey survived.

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Iraqi refugees fleeing ISIS – The militant group ISIS, which now calls itself the Islamic State, executes civilians who don't adhere to its version of Sunni Islam.

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Iraqi refugees fleeing ISIS – Yazidis fled into the barren and windswept Sinjar Mountains more than a week ago after ISIS captured their town.

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Iraqi refugees fleeing ISIS – Descendants of Kurds and followers of an ancient pre-Islamic religion, Yazidis are one of Iraq's smallest minorities, and have been persecuted for centuries, but they have a strong sense of community.

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Iraqi refugees fleeing ISIS – According to some accounts, Syrian Kurds also helped people use parts of northeastern Syria under their control to reach Kurdish areas of northern Iraq.

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Iraqi refugees fleeing ISIS – A young refugee carries a disabled man across the bridge.

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Iraqi refugees fleeing ISIS – Thousands trudge across a river to seek humanitarian aid in Syria.

Iraqi refugees fleeing ISIS – A senior Kurdish official estimated that as many as 70,000 people remain trapped on Mount Sinjar, and that at least 100 have died so far from dehydration and the heat. CNN could not independently confirm those estimates.

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Iraqi refugees fleeing ISIS – A man weeps after been reunited with his family.

A colonel with the Peshmerga told CNN the operation began early Saturday with Kurdish forces advancing toward the dam as the United States carried out airstrikes against "mobile ISIS positions."

The dam complex has not been hit, the colonel said on condition of anonymity. He is not authorized to speak to the media.

While Peshmerga spokesman Hilgurd Hikmat also confirmed the U.S. airstrikes, he said the Kurdish forces are not on the move and have not engaged in battle with ISIS fighters near the dam.

Mosul Dam is under ISIS control, but it is still up and running, the colonel said. Engineers and employees remain at work, he said.

U.S. intelligence agencies, according to the U.S. official, are also keeping an eye on the Haditha Dam on the Euphrates River in Iraq's western Anbar province, where Iraqi troops have been holding off an ISIS assault for weeks.

The dam is the second-largest in the country, and it provides water to western and southern Iraq. A failure of the Haditha Dam also would prove catastrophic.

Earlier this year, ISIS fighters opened the gates on the Falluja dam after seizing it in an effort to stop an Iraqi military advance. The water from the dam flooded a number of small villages.

U.S. President Barack Obama ordered targeted airstrikes to protect U.S. personnel and facilities in Iraq and prevent a potential genocide of ethnic and religious minority groups by ISIS, also known as the Islamic State in Iraq and Syria.

American airstrikes were carried out near the Yazidi village of Kojo amid reports that ISIS fighters had launched an attack, the U.S. military said.

Yazidi men killed, women abducted

ISIS swept into the village on Friday, killing at least 80 men and taking more than 100 women captive, officials told CNN. One Yazidi leader put the death toll much higher.

The report of the brutal attack on the village of Kojo came after Obama -- citing the success of targeted American airstrikes -- declared an end to an ISIS siege that had trapped tens of thousands of Yazidis in mountains.

A Yazidi leader, Mirza Dinnayi, told British broadcaster Channel Four News that more than 350 men were killed and 1,000 women and children kidnapped during the attack.

Fighters with ISIS attacked Kojo after surrounding it for days, a Kurdish regional government official and a Yazidi religious leader said.

The women abducted from the village were being taken to the ISIS-controlled northern cities of Mosul and Tal Afar, the official said.

CNN cannot independently confirm the killings and abductions, but the claims are similar to reports provided by survivors of ISIS attacks in Iraq.

The Yazidis, one of Iraq's smallest and oldest religious minorities, are among 400,000 people that the United Nations estimates have been driven from their homes since June, when ISIS swept across the border from Syria into Iraq.